The invention relates to the field of mechanical connecting devices for optical conductors and can be used for the structural design of multichannel multifiber connectors which can be mated and in which the connector housings are provided with alignment aids for lining up the individual plug connectors, which are arranged in the connector housing, with one another.
In multiway connectors of this type, individual plug connectors, which are also referred to as optical end pieces or ferrules, are float-mounted in the common connector housing. The individual plug connectors each terminate one or more optical conductors at the end, in such a manner that the optical conductors end on a coupling end surface which is suitable for optical coupling to an opposing coupling partner.
For the purposes of the present invention, the term optical conductor means a conductor which is suitable for carrying and passing on an optical signal, such as prefabricated optical conductor cables, optical conductor strips or optical conductors formed on a substrate (so-called xe2x80x9cwaveguidesxe2x80x9d). The individual plug connectors, and thus the optical conductor ends (coupling partners) held by them must be positioned highly accurately with respect to one another. To this end, the individual plug connectors are normally provided with corresponding alignment elements; the alignment elements comprise, for example, centering pins which extend in front of the other items out of the coupling end face of one individual plug connector in the mating direction, and complementary alignment elements in the form of holes, which are matched to the centering pins, on the other individual plug connector. Since the physical dimensions are comparatively small overall, these alignment means can be stressed only lightly in mechanical terms and they allow alignment only if adequate prealignment of the coupling partners with respect to one another is ensured.
In one prior art optical connector system, alignment aids are provided on the two connector housing and align the connector housings directly with respect to one another when the multiway connectors are mated, before alignment elements of the individual plug connectors start to cooperate, providing fine alignment of the individual plug connectors to be coupled with the alignment elements of the individual plug connectors on the opposing multiway connector. There, one connector housing is detachably mechanically fixed via locking elements in a guide bush which is used to accomodate the other connector housing, with the second connector housing being latched to the first connector housing by means of spring-loaded alignment aids (see European published patent application EP 0 807 837 A1).
In another prior art optical connector system, the two connector housings are held together by friction forces between alignment aids which are relatively long in the axial direction of the connector system and are designed differently on the two connector housings (see International PCT publication WO 97/34176 A1).
In a further prior art optical connector system, the two connector housings, which are provided with different alignment aids, are inserted into a bush which is used for prior alignment of the connector housing and which is latched to one connector housing (see German paten DE 19539549 C1). When the two connector housings are mated in the bush, the tolerance elements of both the bush and the connector housings as well as the clearance fits to be provided between these elements have an additive effect, which is disadvantageous from the point of view of prealignment of the alignment elements of the individual plug connectors.
It is accordingly an object of the invention to provide an optical connector system, which overcomes the above-mentioned disadvantages of the heretofor-known devices and methods of this general type and which is refining such that higher precision for the mutual alignment is achieved by decoupling the mutual alignment of the connector housings from their mutual fixation.
With the foregoing and other object in view there is provided, in accordance with the invention, an optical connector system, comprising:
two multiway connectors each having a connector housing with a longitudinal axis and a plurality of individual plug connectors float-mounted in the connector housing;
a plurality of alignment aids on the connector housing and an individual alignment element on each of the individual plug connectors;
the connector housings of the two multiway connectors being provided with substantially identical alignment aids disposed such that, when one of the multiway connectors is rotated through 180xc2x0 about the longitudinal axis thereof with respect to the other one of the multiway connectors, the alignment aids cooperate with one another; and
a coupling bush for axially fixing the housings of the two connectors to one another in a mating position thereof.
In other words, the objects of the invention are satisfied with the two connector housings that are each provided with the same alignment aids. Further, the alignment aidsxe2x80x94when one multiway connector is rotated through 180xc2x0 about its longitudinal axis with respect to the other multiway connectorxe2x80x94cooperate with one another, and in that the two connector housings are fixed axially to one another by means of a coupling bush.
For the purposes of the invention, the term alignment aid means mechanical elements whose design and shape mean that they are suitable for contributing to the mutual prealignment of the connector housings; in particular, webs, tongue and groove combinations, guide surfaces or pins are suitable for use as alignment aids.
One major advantage of the new connector system is that, by forming identical alignment aids on both connector housings, their tolerances and the necessary clearance fits are reduced, so that the alignment aids are prealigned with respect to one another over a tolerance band which is comparatively small. During the rest of the mating process, only minor alignment movements of the individual plug connectors to be coupled are then required. This significantly increases their life, which is dependent on the number of mating cycles, and the reproducibility of the optical coupling quality (coupling efficiency) is considerably increased. In this case, the coupling bush carries out only tasks related to mechanical fixing after completion of the mating process, although coupling bush production tolerances do not affect the mutual positioning of the individual plug connectors.
In accordance with an added feature of the invention, the alignment aids are tab-shaped projections on the face edge of the connector housing. This refinement of the connector system is preferred with regard to production engineering and handling. In addition to their alignment function, the projections which project beyond the end edge of the connector housing can advantageously provide reliable protection of the sensitive ends and alignment elements of the individual plug connectors.
In accordance with an additional feature of the invention, the projections extend by different amounts, seen in the mating direction of the connectors. This development of the invention is advantageous for a step-by-step prealignment process during the mating process and with respect to the use of connector housings of identical design.
In accordance with another feature of the invention, each of the connector housings has a longitudinal edge, a top, and a bottom, and the alignment aids are arranged on the longitudinal edges and in a central area of the top and the bottom of the connector housing. The cited protective function of the alignment aids is reinforced in accordance with this further advantageous refinement of the invention.
In accordance with a concomitant feature of the invention, the two connectors are mateable in a defined mating direction, and at least one of the alignment aids forms a limit stop to a movement of the connector housing in at least two degrees of freedom at right angles to the mating direction. This is particularly advantageous for handling and with respect to having as small a number of alignment aids as possible.
Other features which are considered as characteristic for the invention are set forth in the appended claims.
Although the invention is illustrated and described herein as embodied in an optical connector system, it is nevertheless not intended to be limited to the details shown, since various modifications and structural changes may be made therein without departing from the spirit of the invention and within the scope and range of equivalents of the claims.
The construction and method of operation of the invention, however, together with additional objects and advantages thereof will be best understood from the following description of specific embodiments when read in connection with the accompanying drawing.